The Experts below are selected from a list of 1251 Experts worldwide ranked by ideXlab platform
Jianlin Yu - One of the best experts on this subject based on the ideXlab platform.
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Theoretical study on a novel R32 Refrigeration Cycle with a two-stage suction ejector
International Journal of Refrigeration-revue Internationale Du Froid, 2020Co-Authors: Jianlin Yu, Xin Song, Ming MaAbstract:Abstract This paper presents a new ejector enhanced vapor Compression Refrigeration Cycle operating with the refrigerant R32. In this Cycle, an ejector with two suction inlets is employed to recover the expansion process losses of the Cycle. The theoretical model for the developed Cycle is established and the performance of this Cycle using refrigerant R32 is investigated. Furthermore, the performance comparisons of the developed Cycle, basic vapor Compression Refrigeration Cycle and conventional ejector expansion Refrigeration Cycle have also been carried out. The theoretical study shows that the developed Cycle gives a higher cooling (heating) capacity and a higher coefficient of performance. The newly developed Cycle could make a contribution for the application of refrigerant R32 in air-conditioner systems.
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Theoretical investigation on the performance of an ejector enhanced Refrigeration Cycle using hydrocarbon mixture R290/R600a
Applied Thermal Engineering, 2020Co-Authors: Qi Chen, Yunho Hwang, Jianlin YuAbstract:Abstract This paper proposes an ejector enhanced vapor Compression Refrigeration Cycle (EVRC) using zeotropic hydrocarbon mixture R290/R600a for applications in domestic refrigerator/freezers. An internal heat exchanger and a phase separator are utilized in EVRC to improve the system performance. An ejector is adopted to further enhance the Cycle performance. The energy and exergy analysis of EVRC are performed to evaluate the system operating characteristics and compared with the Lorenz-Meutzer vapor Compression Refrigeration Cycle (LVRC) and the traditional vapor Compression Refrigeration Cycle (TVRC). The results indicate that EVRC can provide the uppermost advantages over both TVRC and LVRC under the operating conditions. Compared with TVRC, the EVRC can significantly improve the coefficient of performance, volumetric Refrigeration capacity and exergy efficiency by 13.5%, 19.3%, and 13.4%, respectively. The performance characteristics of the proposed Cycle demonstrate its potential advantages for application in domestic refrigerator/freezers.
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Theoretical investigation on the performance of a modified Refrigeration Cycle with R170/R290 for freezers application
International Journal of Refrigeration-revue Internationale Du Froid, 2019Co-Authors: Qi Chen, Le Zhou, Jianlin YuAbstract:Abstract This study presents a modified vapor Compression Refrigeration Cycle (MVRC) with zeotropic mixture R170/R290 for freezers. Different from the conventional vapor Compression Refrigeration Cycle (CVRC), two separators and corresponding capillary tubes are employed into MVRC to achieve partial-condensation separation and flash separation for a composition shift effect, respectively. MVRC can provide the Cycle performance improvement due to the composition shift effect of zeotropic mixture. The mathematical model based on energetic and exergetic methods is developed to evaluate the Cycle operating performance of MVRC and compare with that of CVRC. The results show that MVRC is more promising for low-temperature cooling system over CVRC. Under the given operation condition, the Cycle performance improvement of MVRC over CVRC in terms of coefficient of performance (COP), volumetric cooling capacity and exergy efficiency can reach up to 12.7%, 32.6% and 20%, respectively. The performance characteristics of the proposed Cycle demonstrate its potential advantages for application in the freezers.
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Performance analysis of an ejector enhanced Refrigeration Cycle with R290/R600a for application in domestic refrigerator/freezers
Applied Thermal Engineering, 2017Co-Authors: Qi Chen, Jianlin YuAbstract:Abstract This study presents an ejector enhanced vapor Compression Refrigeration Cycle (EVRC) using zeotropic mixture R290/R600a for domestic refrigerator/freezers. An ejector and a phase separator are adopted in EVRC to enhance the Cycle performance. Energetic and exergetic analysis methods are utilized to theoretically investigate the system operating performance of EVRC and compared with the traditional vapor Compression Refrigeration Cycle (TVRC). The results demonstrate that EVRC outperforms TVRC and exhibits higher coefficient of performance (COP), volumetric cooling capacity and exergy efficiency. Under the given operation condition, the system performance improvement of EVRC over TVRC in the aspect of COP, volumetric cooling capacity and exergy efficiency can reach up to 14.2%, 37% and 17.7%, respectively. The performance characteristics of the proposed novel Cycle show its potential advantages for application in domestic refrigerator/freezers.
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Performance analysis of a modified zeotropic mixture (R290/R600) Refrigeration Cycle with internal subcooler for freezer applications
Applied Thermal Engineering, 2016Co-Authors: Qi Chen, Jianlin YuAbstract:Abstract This study presents a modified vapor Compression Refrigeration Cycle (MVRC) using zeotropic mixture R290/R600 for freezers. In the MVRC, an internal subcooler with additional bypass tube is introduced to enhance the overall system performance. Energetic and exergetic analysis methods are introduced to theoretically evaluate the system operating performance, and compared with the performance of the traditional vapor Compression Refrigeration Cycle (TVRC). The results show that the MVRC yields higher Refrigeration coefficient of performance (COP), volumetric cooling capacity and exergy efficiency than the TVRC. Under the given condition, the COP, volumetric cooling capacity and exergy efficiency of MVRC could be improved by up to an average of 8.9%, 12.4% and 10.4%. Moreover, COP and exergy efficiency of MVRC increases with the rising bypass coefficient of the refrigerant. The performance characteristics of the proposed novel Cycle demonstrate the potential advantages for application in freezer systems.
Guangming Chen - One of the best experts on this subject based on the ideXlab platform.
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exergetic and economic analyses of a novel modified solar heat powered ejection Compression Refrigeration Cycle comparing with conventional Cycle
Energy Conversion and Management, 2018Co-Authors: Yingjie Xu, Ning Jiang, Qin Wang, Mengjie Song, Guangming ChenAbstract:Abstract In this paper, a novel modified ejection-Compression Refrigeration Cycle is studied and compared with conventional ejection-Compression Refrigeration Cycle based on exergetic and economic analyses. The novel Cycle is expected to improve the low practicability of conventional ejection-Compression Cycle with better thermal efficiency, smaller solar collector and more excellent economic performance. Energy performance is simply evaluated based on thermal efficiency and global coefficient of performance. The results show the novel Cycle is better in both the two indicators, which confirmed that it needs much less solar heat and smaller collector, and has better practicability. With the above data, exergy analysis is performed, showing the total exergy destruction of the novel Cycle is 23.97 kW less than a conventional Cycle and exergy efficiency of the novel Cycle is always higher than the conventional Cycle in the studied range. Economic analyses taking into consideration the impact of carbon dioxide emission are finished under base case. The results reveal the novel Cycle has a total cost rate 24.4% lower and a solar collector 89.5% smaller than those of a conventional Cycle. The economic advantage of the novel Cycle will remain, even both electricity price and carbon dioxide penalty cost increase to 3.1 times of the current price. These improvements in energy and economy indicate the novel Cycle has an excellent application potential.
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refrigerant evaluation and performance comparison for a novel hybrid solar assisted ejection Compression Refrigeration Cycle
Solar Energy, 2018Co-Authors: Yingjie Xu, Ning Jiang, Qin Wang, Guangming ChenAbstract:Abstract This paper presents an investigation on refrigerant evaluation and performance comparison of a novel solar-powered hybrid ejection-Compression Cycle for space cooling or Refrigeration. By reducing heat consumption and solar collector area, the novel ejection-Compression Cycle can have better practicality and performance than conventional hybrid ejection-Compression Cycle. A model for the novel hybrid Cycle is proposed including a validated 1-D ejector model. Five refrigerants are selected from a series of candidate refrigerants and are further evaluated based on Cycle performance. Finally, R152a is recommended for its good characteristics and performance. With R152a, the novel Cycle is compared with conventional Cycle. The results show that the novel Cycle has both higher electric efficiency (COPele) and thermal efficiency (COPth), when rationally low solar heat is provided. At low heat region and Tg = 90 °C, the novel Cycle only consumes 66.6 kW heat to increase COPele from 3.01 to 3.76, while the traditional Cycle consumes 3 times the solar heat to achieve the same COPele. When more heat is consumed, the COPele of conventional Cycle increases. However, the increasing installation space and capital cost of increasing collector greatly reduce the practicality of conventional Cycle. Therefore, the novel Cycle has better feasibility and good energy performance.
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proposal and thermodynamic analysis of an ejection Compression Refrigeration Cycle driven by low grade heat
Energy Conversion and Management, 2017Co-Authors: Yingjie Xu, Ning Jiang, Qin Wang, Guangming ChenAbstract:Abstract Ejection-Compression Refrigeration Cycle reduces electricity consumption, by using huge quantity of low-grade heat, which increases equipment cost and occupies more space, especially when it is powered by solar heat. Hence, the large solar collector limits the practicability of ejection-Compression Refrigeration Cycle. To solve this problem, a novel ejection-Compression Refrigeration Cycle is proposed in this paper, which needs less heat and a smaller collector. It is theoretically compared to conventional vapor Compression Refrigeration Cycle and conventional ejection-Compression Refrigeration Cycle. It is also analyzed over wide temperature ranges. Results show that the proposed Cycle has a COP 24% higher than conventional vapor Compression Cycle. The proposed Cycle also has a COP 19% lower, heat transforming ratio 181% higher, and COP g 144% higher than those of conventional ejection-Compression Cycle. With a collector 5 times smaller than a conventional ejection-Compression Cycle, the novel Cycle is suitable for city buildings with limited space or economy sensitive users, although its COP is a little lower than conventional ejection-Compression Cycle. The effects of evaporating, condensing, generating, and intermediate temperatures ( T e , T c , T g , and T m ) on Cycle performance are explained. At T m = 10 °C, the maximum COP of 4.78 is obtained with the optimized generation temperatures of 72 °C.
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Comparative study on two low-grade heat driven absorption-Compression Refrigeration Cycles based on energy, exergy, economic and environmental (4E) analyses
Energy Conversion and Management, 2017Co-Authors: Yingjie Xu, Ning Jiang, Qin Wang, Guangming ChenAbstract:Absorption-Compression Refrigeration Cycle is widely studied for its energy saving potential. In this paper, a comparative study on a novel absorption-Compression Cycle with an evaporator-subcooler (ES) and a conventional absorption-Compression Refrigeration Cycle with an evaporator-condenser (EC) has been done for the first time. The comparative investigation is based on energy, exergy, economic and environmental (4E) analyses. The results show EC saves 22.5% more electric energy than ES at the cost of consuming 4.6 times more low-grade heat energy than ES. EC has a higher COP, but has a lower COPg, which takes into account both electric power and low-grade heat power. From the exergy analysis, the exergy efficiency of ES is 31.6%, 54.1% higher than EC’s (20.5%), indicating ES has a much better exergy performance. The economic analysis shows that when waste heat is used, EC has a better economic performance and when solar heat is used, ES has better practical application potential. The effect of electricity price and CO2 tax rate on economic performance is also studied. The better Cycle for different electricity price and CO2 tax rate are recommended. The results and understanding of the two Cycles can be used as the basis for Cycle selection and design.
Yingjie Xu - One of the best experts on this subject based on the ideXlab platform.
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exergetic and economic analyses of a novel modified solar heat powered ejection Compression Refrigeration Cycle comparing with conventional Cycle
Energy Conversion and Management, 2018Co-Authors: Yingjie Xu, Ning Jiang, Qin Wang, Mengjie Song, Guangming ChenAbstract:Abstract In this paper, a novel modified ejection-Compression Refrigeration Cycle is studied and compared with conventional ejection-Compression Refrigeration Cycle based on exergetic and economic analyses. The novel Cycle is expected to improve the low practicability of conventional ejection-Compression Cycle with better thermal efficiency, smaller solar collector and more excellent economic performance. Energy performance is simply evaluated based on thermal efficiency and global coefficient of performance. The results show the novel Cycle is better in both the two indicators, which confirmed that it needs much less solar heat and smaller collector, and has better practicability. With the above data, exergy analysis is performed, showing the total exergy destruction of the novel Cycle is 23.97 kW less than a conventional Cycle and exergy efficiency of the novel Cycle is always higher than the conventional Cycle in the studied range. Economic analyses taking into consideration the impact of carbon dioxide emission are finished under base case. The results reveal the novel Cycle has a total cost rate 24.4% lower and a solar collector 89.5% smaller than those of a conventional Cycle. The economic advantage of the novel Cycle will remain, even both electricity price and carbon dioxide penalty cost increase to 3.1 times of the current price. These improvements in energy and economy indicate the novel Cycle has an excellent application potential.
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refrigerant evaluation and performance comparison for a novel hybrid solar assisted ejection Compression Refrigeration Cycle
Solar Energy, 2018Co-Authors: Yingjie Xu, Ning Jiang, Qin Wang, Guangming ChenAbstract:Abstract This paper presents an investigation on refrigerant evaluation and performance comparison of a novel solar-powered hybrid ejection-Compression Cycle for space cooling or Refrigeration. By reducing heat consumption and solar collector area, the novel ejection-Compression Cycle can have better practicality and performance than conventional hybrid ejection-Compression Cycle. A model for the novel hybrid Cycle is proposed including a validated 1-D ejector model. Five refrigerants are selected from a series of candidate refrigerants and are further evaluated based on Cycle performance. Finally, R152a is recommended for its good characteristics and performance. With R152a, the novel Cycle is compared with conventional Cycle. The results show that the novel Cycle has both higher electric efficiency (COPele) and thermal efficiency (COPth), when rationally low solar heat is provided. At low heat region and Tg = 90 °C, the novel Cycle only consumes 66.6 kW heat to increase COPele from 3.01 to 3.76, while the traditional Cycle consumes 3 times the solar heat to achieve the same COPele. When more heat is consumed, the COPele of conventional Cycle increases. However, the increasing installation space and capital cost of increasing collector greatly reduce the practicality of conventional Cycle. Therefore, the novel Cycle has better feasibility and good energy performance.
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proposal and thermodynamic analysis of an ejection Compression Refrigeration Cycle driven by low grade heat
Energy Conversion and Management, 2017Co-Authors: Yingjie Xu, Ning Jiang, Qin Wang, Guangming ChenAbstract:Abstract Ejection-Compression Refrigeration Cycle reduces electricity consumption, by using huge quantity of low-grade heat, which increases equipment cost and occupies more space, especially when it is powered by solar heat. Hence, the large solar collector limits the practicability of ejection-Compression Refrigeration Cycle. To solve this problem, a novel ejection-Compression Refrigeration Cycle is proposed in this paper, which needs less heat and a smaller collector. It is theoretically compared to conventional vapor Compression Refrigeration Cycle and conventional ejection-Compression Refrigeration Cycle. It is also analyzed over wide temperature ranges. Results show that the proposed Cycle has a COP 24% higher than conventional vapor Compression Cycle. The proposed Cycle also has a COP 19% lower, heat transforming ratio 181% higher, and COP g 144% higher than those of conventional ejection-Compression Cycle. With a collector 5 times smaller than a conventional ejection-Compression Cycle, the novel Cycle is suitable for city buildings with limited space or economy sensitive users, although its COP is a little lower than conventional ejection-Compression Cycle. The effects of evaporating, condensing, generating, and intermediate temperatures ( T e , T c , T g , and T m ) on Cycle performance are explained. At T m = 10 °C, the maximum COP of 4.78 is obtained with the optimized generation temperatures of 72 °C.
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Comparative study on two low-grade heat driven absorption-Compression Refrigeration Cycles based on energy, exergy, economic and environmental (4E) analyses
Energy Conversion and Management, 2017Co-Authors: Yingjie Xu, Ning Jiang, Qin Wang, Guangming ChenAbstract:Absorption-Compression Refrigeration Cycle is widely studied for its energy saving potential. In this paper, a comparative study on a novel absorption-Compression Cycle with an evaporator-subcooler (ES) and a conventional absorption-Compression Refrigeration Cycle with an evaporator-condenser (EC) has been done for the first time. The comparative investigation is based on energy, exergy, economic and environmental (4E) analyses. The results show EC saves 22.5% more electric energy than ES at the cost of consuming 4.6 times more low-grade heat energy than ES. EC has a higher COP, but has a lower COPg, which takes into account both electric power and low-grade heat power. From the exergy analysis, the exergy efficiency of ES is 31.6%, 54.1% higher than EC’s (20.5%), indicating ES has a much better exergy performance. The economic analysis shows that when waste heat is used, EC has a better economic performance and when solar heat is used, ES has better practical application potential. The effect of electricity price and CO2 tax rate on economic performance is also studied. The better Cycle for different electricity price and CO2 tax rate are recommended. The results and understanding of the two Cycles can be used as the basis for Cycle selection and design.
F A Holland - One of the best experts on this subject based on the ideXlab platform.
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ammonia lithium nitrate absorption Compression Refrigeration Cycle part ii experimental
Applied Thermal Engineering, 1998Co-Authors: R Ayala, C L Heard, F A HollandAbstract:The combination of an ammonia/lithium nitrate absorption Refrigeration system with an ammonia mechanical vapour Compression system can enhance the efficiency of the overall system. Based on the primary energy ratio this kind of hybrid system can operate more efficiently in developing countries than in developed ones. This is because electricity is generated and distributed less efficiently in developing countries. A 7 kWt prototype of a hybrid system was fabricated and commissioned, and the experimental results are presented. The maximum COP was obtained using 90% Compression and 10% absorption. For this Compression proportion, it was not necessary to supply heat to drive the absorption section, since the heat is supplied by the superheated ammonia at the compressor outlet.
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ammonia lithium nitrate absorption Compression Refrigeration Cycle part i simulation
Applied Thermal Engineering, 1997Co-Authors: R Ayala, C L Heard, F A HollandAbstract:Ammonia/lithium nitrate absorption Refrigeration combined with mechanical vapour Compression in the same circuit permits higher efficiencies than individual Compression or absorption Cycles. The absorption Cycle produces pure ammonia refrigerant and is thus suitable for retrofitting projects in existing ammonia mechanical vapour Compression plants. The Cycle is modelled over a range of proportions from 0 to 100% mechanical vapour Compression. Different power generation and distribution efficiencies are considered in deriving the primary energy ratios. These efficiencies are related to the differences between the level of industrial development in various countries. In general it is possible to achieve up to a 10% increase in overall efficiency using combined absorption/Compression Refrigeration systems.
Thanarath Sriveerakul - One of the best experts on this subject based on the ideXlab platform.
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analysis of a combined rankine vapour Compression Refrigeration Cycle
Energy Conversion and Management, 2010Co-Authors: Satha Aphornratana, Thanarath SriveerakulAbstract:Abstract This paper describes a theoretical analysis of a heat-powered Refrigeration Cycle, a combined Rankine–vapour–Compression Refrigeration Cycle. This Refrigeration Cycle combines an Organic Rankine Cycle and a vapour–Compression Cycle. The Cycle can be powered by low grade thermal energy as low as 60 °C and can produce cooling temperature as low as −10 °C. In the analysis, two combined Rankine–vapour–Compression Refrigeration Cycles were investigated: the system with R22 and the system with R134a. Calculated COP values between 0.1 and 0.6 of both the systems were found.
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Analysis of a combined Rankine–vapour–Compression Refrigeration Cycle
Energy Conversion and Management, 2010Co-Authors: Satha Aphornratana, Thanarath SriveerakulAbstract:Abstract This paper describes a theoretical analysis of a heat-powered Refrigeration Cycle, a combined Rankine–vapour–Compression Refrigeration Cycle. This Refrigeration Cycle combines an Organic Rankine Cycle and a vapour–Compression Cycle. The Cycle can be powered by low grade thermal energy as low as 60 °C and can produce cooling temperature as low as −10 °C. In the analysis, two combined Rankine–vapour–Compression Refrigeration Cycles were investigated: the system with R22 and the system with R134a. Calculated COP values between 0.1 and 0.6 of both the systems were found.